Dibrugarh/Jorhat, May 12: Suspected Ulfa militants damaged a pipeline of the state-run Assam Gas Company Limited (AGCL) near Borhat tea estate in Sivasagar district last night.

In another incident, suspected Ulfa rebels brutally assaulted Congress worker Bibha Bora (35) in Lakhimpur town late last night for allegedly informing police that she had received a Rs 10-lakh extortion note. Her private security officer and husband fled when she was attacked, sources said.

The Sivasagar blast damaged 12 metres of the 16-inch trunk pipeline, cutting off gas supply to the Lakwa thermal power station and resulting in a massive shortfall in its feedstock.

The pipeline is the only route through which natural gas is supplied to the station, which then supplies power to the Upper Assam tea gardens. Around 50 tea estates, especially in Jorhat and Golaghat districts, are likely to face a power crisis till supply is restored.

Dipak Chetia Phukon, public relations manager of the Duliajan-based AGCL, said: “Gas supply to the power station through the Duliajan-Namrup-Lakwa pipeline was stopped around midnight after we received information about the blast.” He said it would take a couple of days for the pipeline to be repaired and normal gas supply to resume.

This is the second blast carried out by Ulfa in Sivasagar district within 48 hours. The outfit had triggered a blast inside a pharmacy in Sivasagar town on Thursday.

Last night, another major tragedy was averted at Bharalumukh in Guwahati when a powerful improvised explosive device was defused after a housewife alerted the police.

The incident at Sivasagar could not have come at a more inoppotune time as the power situation in the state is already precarious. Besides, protests over army atrocities continued at Doomdooma over the killing of Budheswar Moran by the army last weekend.